Up to now, as a method of controlling an EGR valve, a differential pressure before and after the EGR valve is measured by a differential pressure sensor, and the EGR valve is controlled based on a measurement result (for instance, Japanese Unexamined Application Publication (JP-A) No. 2004-150343.
However, the method disclosed in JP-A No. 2004-150343 suffers from such a problem that the differential pressure sensor that measures the differential pressure before and after the EGR valve needs to be disposed in the vicinity of the EGR valve, resulting in a complicated configuration.